Reduced shank bits, also known as blacksmith drills, have a straight shank narrower than the diameter so they can be fitted into chucks that are not able to hold the entire diameter. Parabolic flute bits are for deep hole drilling at higher feed rates
Warning:This product may expose you to chemicals including Cobalt, a chemical known to the State of California to cause Cancer. For more information go to www.P65Warnings.ca.gov